Prob. with extra header coming in spool o/ p (spool from program)

Hi

I am implemeting the badi ME_PURCHDOC_POSTED and based upon certain conditions I am writing some field values in spool and later on converting to pdf for sending emails.

The problem is coming in the spool output. The spool ouput contains a extra header line with text "START MEPO" and the current date. Its automatically being written by the standard code. My requirement is to either stop the header from getting printed in spool output or to change the text to something else other than "START MEPO" as per the requirement. My code is

clear wf_pripar.

CALL FUNCTION 'GET_PRINT_PARAMETERS'

EXPORTING

in_parameters = wf_pripar

line_size = 255

layout = 'X_65_255'

no_dialog = 'X'

IMPORTING

out_parameters = wf_pripar

EXCEPTIONS

archive_info_not_found = 1

invalid_print_params = 2

invalid_archive_params = 3

OTHERS = 4.

NEW-PAGE PRINT ON PARAMETERS wf_pripar NO DIALOG .

RESERVE 5 LINES.

**To write PO header details in spool

WRITE : / 'Material #',

19(17) 'Comm Code',

37(10) 'Vendor No'.

:::::::

NEW-PAGE PRINT OFF.

The output spool is:

09-26-2008 Start MEPO 1

________________________________________________________________

Material # Comm Code Vendor No Vendor Name

123 123 asd xyz

The output spool contains an extra header. When we debugged we saw that one standar top-of-page is getting triggered. Please suggest if we need to pass any particular parameter to GET_PRINT_PARAMETERS or any other way to suppress or change the header.